A survey of hundreds of miles of New England and mid-Atlantic coastline found that 68 percent of the beaches studied have eroded during the past 150 years, according to a report released this week.
The average rate of erosion was 1.6 feet per year, including an extreme case of 60 feet in one year, the U.S. Geological Survey report said.
The worst erosion was from New York’s Long Island to the Virginia-North Carolina border, a region with more vulnerable barrier beaches and frequently changing inlet areas. New England’s rockier coasts were receding more slowly, but the percentage of coastline eroding there was higher.
The report also indicated erosion has slowed slightly in the past 25 to 30 years, with the percentage of beaches eroding dropping to 60 percent, perhaps due to beach recovery programs.
Beaches change for a variety of reasons, including storms, rising sea levels, human activities and the amount of sand.
The survey can help with coastal management decisions and provide a foundation for future studies of shoreline movement, coastal erosion or land loss, said the report’s lead author, Cheryl Hapke.
“It is very difficult to predict what may happen in the future without a solid understanding of what has happened in the past,” she said.
The report provides “invaluable objective data” that can help scientists understand changes on the coast that are either natural or caused by humans, said Anne Castle, assistant secretary of the Interior for water and science.
“The information gathered can inform decisions about future land use, transportation corridors and restoration projects,” she said in a news release.
The report is the fifth in a geological survey project to study historical shoreline change around the country, which has growing coastal populations and a wealth of infrastructure that’s vulnerable to erosion.
Previous reports on areas such as the Gulf of Mexico and the southeast Atlantic were less comprehensive than the new report, which studies erosion rates on nearly 80 percent of New England and mid-Atlantic coasts.
Researchers surveyed 21,000 locations over 650 miles of coastline from Maine through Virginia, measuring shoreline changes using old maps and aerial photographs, as well as lidar, which is technology similar to radar that uses light to gather topographical information.
Scientists found that coastal change varied widely. But they said since most of the coast in the New England and mid-Atlantic regions is eroding, that indicates there are widespread erosion hazards.